use crate::io::{LittleEndian, ReadBytesExt};
pub struct Reader<'a> {
bytes: &'a [u8],
step_size: usize,
}
impl<'a> Reader<'a> {
pub(crate) fn new(bytes: &'a [u8], offset: u32, len: u32, step_size: u8) -> Self {
let offset = offset as usize;
let len = len as usize;
let step_size = step_size as usize;
let size = len * step_size;
let end = offset + size;
Self {
#[expect(
clippy::indexing_slicing,
reason = "we consider the caller to be trustworthy"
)]
bytes: &bytes[offset..end],
step_size,
}
}
pub fn len(&self) -> usize {
self.bytes.len() / self.step_size
}
pub(crate) fn get(&self, idx: usize) -> usize {
let offset = idx * self.step_size;
#[expect(
clippy::indexing_slicing,
reason = "we consider the caller to be trustworthy"
)]
let mut bytes = &self.bytes[offset..];
if self.step_size == 2 {
unwrap!(bytes.read_u16::<LittleEndian>()).into()
} else {
unwrap!(bytes.read_u32::<LittleEndian>()) as usize
}
}
}